1. Field
One or more embodiments relate to an apparatus for manufacturing a holographic optical element, and an apparatus for reconstructing a holographic image by using the holographic optical element.
2. Description of the Related Art
Recently, there has been a great demand for a three-dimensional image display device capable of realistically and effectively realizing images in various fields such as movies, games, advertisements, medical imaging, education, military, etc. Accordingly, various techniques for displaying a three-dimensional image have been proposed, and various three-dimensional image display devices have already been commercialized.
Three-dimensional image display devices include, for example, a glasses type and a non-glasses type. Furthermore, the glasses type includes a polarized glasses type and a shutter glasses type. The non-glasses type includes a stereoscopy type which includes a lenticular type using a plurality of cylindrical lens arrays and a parallax barrier type having a plurality of barriers and openings.
A hologram method and an integral imaging method have been proposed as a three-dimensional image display method in which depth perception recognized by the brain matches the focal point of the eyes and which can provide full parallax.
A hologram, which is a medium on which a light wave is recorded, stores intensity and phase information of the light wave. While ordinary photographs only record intensity information, holograms store both intensity and phase, thus enabling three-dimensional reconstruction of visual information. For recording a hologram, two beams including a signal beam and a reference beam, both having coherence, are required. The signal beam is a beam that can be modulated from an object to be recorded. The intensity or phase information of an interference pattern between the signal beam and the reference beam is recorded in a hologram recording medium, and thus the intensity or phase information of a modulated signal beam can be recorded. When a beam having the same optical characteristics as the reference beam used for recording is incident on the recorded hologram, the signal beam stored in the hologram can be reproduced.